Article

Adoptive transfer of tumor-reactive transforming growth factor-beta-insensitive CD8+ T cells: eradication of autologous mouse prostate cancer.

Department of Urology, Northwestern University's Feinberg School of Medicine, Chicago, Illinois 60611, USA.
Cancer Research (impact factor: 7.86). 04/2005; 65(5):1761-9. DOI:10.1158/0008-5472.CAN-04-3169 pp.1761-9
Source: PubMed

ABSTRACT Transforming growth factor (TGF)-beta is a potent immunosuppressant. Overproduction of TGF-beta by tumor cells may lead to tumor evasion from the host immune surveillance and tumor progression. The present study was conducted to develop a treatment strategy through adoptive transfer of tumor-reactive TGF-beta-insensitive CD8+ T cells. The mouse TRAMP-C2 prostate cancer cells produced large amounts of TGF-beta1 and were used as an experimental model. C57BL/6 mice were primed with irradiated TRAMP-C2 cells. CD8+ T cells were isolated from the spleen of primed animals, were expanded ex vivo, and were rendered TGF-beta insensitive by infecting with a retrovirus containing dominant-negative TGF-beta type II receptor. Results of in vitro cytotoxic assay revealed that these CD8+ T cells showed a specific and robust tumor-killing activity against TRAMP-C2 cells but were ineffective against an irrelevant tumor line, B16-F10. To determine the in vivo antitumor activity, recipient mice were challenged with a single injection of TRAMP-C2 cells for a period up to 21 days before adoptive transfer of CD8+ T cells was done. Pulmonary metastasis was either eliminated or significantly reduced in the group receiving adoptive transfer of tumor-reactive TGF-beta-insensitive CD8+ T cells. Results of immunofluorescent studies showed that only tumor-reactive TGF-beta-insensitive CD8+ T cells were able to infiltrate into the tumor and mediate apoptosis in tumor cells. Furthermore, transferred tumor-reactive TGF-beta-insensitive CD8+ T cells were able to persist in tumor-bearing hosts but declined in tumor-free animals. These results suggest that adoptive transfer of tumor-reactive TGF-beta-insensitive CD8+ T cells may warrant consideration for cancer therapy.

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Keywords

adoptive transfer
 
cancer therapy
 
CD8+ T cells
 
ex vivo
 
experimental model
 
host immune surveillance
 
irradiated TRAMP-C2 cells
 
irrelevant tumor line
 
large amounts
 
mouse TRAMP-C2 prostate cancer cells
 
robust tumor-killing activity
 
TRAMP-C2 cells
 
Transforming growth factor
 
treatment strategy
 
tumor evasion
 
tumor progression
 
tumor-bearing hosts
 
tumor-free animals
 
vitro cytotoxic assay
 
vivo antitumor activity